STM32独立看门狗和低功耗模式RTC定时唤醒来喂狗.doc

STM32独立看门狗和低功耗模式_RTC定时唤醒来喂狗在STM32开发中经常会用到独立看门狗（IWDG）和低功耗模式，看门狗是为了检测和解决由软件错误引起的故障，低功耗模式是为了在CPU不需要继续运行时进入到休眠模式用以节省电能。其中独立看门狗的时钟由独立的RC振荡器（STM32F10x一般为40kHz）提供，即使在主时钟出现故障时，也仍然有效，因此可以在停止和待机模式下工作。而且独立看门狗一旦启动，除了系统复位，它不能再被停止。但这样引发的一个问题是当MCU进入到低功耗模式后由于CPU停止运行无法喂狗，会导致系统频繁复位。那如何解决这个问题呢，难道独立看门狗和低功耗模式没法同时使用？一个很好的方式是在休眠模式下通过RTC定时唤醒来喂狗，喂完够在进入继续进入到休眠模式。比如看门狗复位的时间间隔为10s。那么在进入休眠模式前设置RTC闹钟中断时间为5s。这样每隔5s唤醒一次喂一次狗。便可以很好的解决这个问题。while(1) / 执行任务 Task1(); Task2(); / . / 喂狗 dev_iwdg_feed(); / 进入待机模式开关 if(m_bEnterStandByMode) / 使能外部中断，GPIOB3，用以MCU从待机模式唤醒 dev_exTI_enable(TRUE); ENTERSTOPMODE: / 设置RTC闹钟，5秒钟产生一次RTC闹钟中断*/ dev_rtc_setAlarm(5); / 进入停止模式（低功耗），直至外部中断触发时被唤醒 PWR_EnterSTOPMode(PWR_Regulator_LowPower, PWR_STOPEntry_WFI); / 是否是RTC闹钟中断唤醒 if(dev_rtc_isAlarm() / 喂狗 dev_iwdg_feed(); / 喂完狗继续进入停止模式 goto ENTERSTOPMODE; / 禁止外部中断 dev_exTI_enable(FALSE); / 从停止模式唤醒后恢复系统时钟 dev_clk_restore(); 以下是完整的参考代码：/* / STM32F10x StopMode RTC Feed Dog / compiler: Keil UV3 / 2013-01-04 , By friehood /* #include stm32f10x_lib.h #include platform_config.h staTIc Boolean g_bRTCAlarm = FALSE; /* * FuncTIon Name : RCC_Configuration * Description : Configures the different system clocks. * Input : None * Output : None * Return : None */ void RCC_Configuration(void) /* RCC system reset(for debug purpose) */ RCC_DeInit(); /* Enable HSE */ RCC_HSEConfig(RCC_HSE_ON); /* Wait till HSE is ready */ if(RCC_WaitForHSEStartUp() = SUCCESS) /* Enable Prefetch Buffer */ FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable); /FLASH时序控制 /推荐值：SYSCLK = 024MHz Latency=0 / SYSCLK = 2448MHz Latency=1 / SYSCLK = 4872MHz Latency=2 /FLASH_SetLatency(FLASH_Latency_1); /警告:修改为1会对DMA值有影响（如ADC采集值会错位） FLASH_SetLatency(FLASH_Latency_2); /* HCLK = SYSCLK */ RCC_HCLKConfig(RCC_SYSCLK_Div1); /* PCLK2 = HCLK */ RCC_PCLK2Config(RCC_HCLK_Div1); /* PCLK1 = HCLK/2 */ RCC_PCLK1Config(RCC_HCLK_Div2); /* PLLCLK = 12MHz * 3 = 36 MHz */ RCC_PLLConfig(RCC_PLLSource_HSE_Div1, RCC_PLLMul_3); /* Enable PLL */ RCC_PLLCmd(ENABLE); /* Wait till PLL is ready */ while(RCC_GetFlagStatus(RCC_FLAG_PLLRDY) = RESET) /* Select PLL as system clock source */ RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK); /* Wait till PLL is used as system clock source */ while(RCC_GetSYSCLKSource() != 0x08) /* Enable PWR and BKP clock */ RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR | RCC_APB1Periph_BKP, ENABLE); /* Enable AFIO clock */ RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE); /* Function Name : NVIC_Configuration* Description : Configures the nested vectored interrupt controller.* Input : None* Output : None* Return : None*/ void NVIC_Configuration(void) NVIC_InitTypeDef NVIC_InitStructure; #ifdef VECT_TAB_RAM /* Set the Vector Table base location at 0x20000000 */ NVIC_SetVectorTable(NVIC_VectTab_RAM, 0x0); #else /* VECT_TAB_FLASH */ /* Set the Vector Table base location at 0x08000000 */ NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0x0); #endif /* Configure one bit for preemption priority */ NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1); /* Function Name : SysTick_Configuration* Description : Configures the SysTick to generate an interrupt each 1 millisecond.* Input : None* Output : None* Return : None*/ void SysTick_Configuration(void) /* Select AHB clock(HCLK) as SysTick clock source */ SysTick_CLKSourceConfig(SysTick_CLKSource_HCLK); /* Set SysTick Priority to 3 */ NVIC_SystemHandlerPriorityConfig(SystemHandler_SysTick, 3, 0); /* SysTick interrupt each 1ms with HCLK equal to 72MHz */ SysTick_SetReload(72000); /* Enable the SysTick Interrupt */ SysTick_ITConfig(ENABLE); /* Function Name : Delay* Description : Inserts a delay time.* Input : nTime: specifies the delay time length, in milliseconds.* Output : None* Return : None*/ void Delay(u32 nTime) /* Enable the SysTick Counter */ SysTick_CounterCmd(SysTick_Counter_Enable); TimingDelay = nTime; while(TimingDelay != 0); /* Disable the SysTick Counter */ SysTick_CounterCmd(SysTick_Counter_Disable); /* Clear the SysTick Counter */ SysTick_CounterCmd(SysTick_Counter_Clear); /* Function Name : RTC_Configuration* Description : Configures RTC clock source and prescaler.* Input : None* Output : Nonevoid RTC_Configuration（void）EXTI_InitTypeDef EXTI_InitStructure;NVIC_InitTypeDef NVIC_InitStructure;/* RTC clock source configuration -*/* Allow access to BKP Domain */PWR_BackupAccessCmd（ENABLE）;/* Reset Backup Domain */BKP_DeInit（）;/* Enable the LSI OSC */RCC_LSICmd（ENABLE）;/* Wait till LSI is ready */while （RCC_GetFlagStatus（RCC_FLAG_LSIRDY） = RESET）/* Select the RTC Clock Source */RCC_RTCCLKConfig（RCC_RTCCLKSource_LSI）;/* Enable the RTC Clock */RCC_RTCCLKCmd（ENABLE）;/* RTC configuration -*/* Wait for RTC APB registers synchronisation */RTC_WaitForSynchro（）;/* Set RTC prescaler： set RTC period to 1sec */RTC_SetPrescaler（40000）;/* Wait until last write operation on RTC registers has finished */RTC_WaitForLastTask（）;/* Enable the RTC Alarm interrupt */RTC_ITConfig（RTC_IT_ALR， ENABLE）;/* Wait until last write operation on RTC registers has finished */RTC_WaitForLastTask（）;/* Configure EXTI Line17（RTC Alarm） to generate an interrupt on rising edge */EXTI_ClearITPendingBit（EXTI_Line17）;EXTI_InitStructure.EXTI_Line = EXTI_Line17;EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising;EXTI_InitStructure.EXTI_LineCmd = ENABLE;EXTI_Init（EXTI_InitStructure）;/* Enable the RTC Interrupt */NVIC_InitStructure.NVIC_IRQChannel = RTCAlarm_IRQChannel;NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;NVIC_Init（NVIC_InitStructure）;/* Function Name ： RTCAlarm_IRQHandler* Description ： This function handles RTC Alarm interrupt request.* Input ： None* Output ： None* Return ： None*/void RTCAlarm_IRQHandler（void）if（RTC_GetITStatus（RTC_IT_ALR） ！= RESET）/* Set the RTC alarm flag */g_bRTCAlarm = TRUE;/* Clear EXTI line17 pending bit */EXTI_ClearITPendingBit（EXTI_Line17）;/* Check if the Wake-Up flag is set */if（PWR_GetFlagStatus（PWR_FLAG_WU） ！= RESET）/* Clear Wake Up flag */PWR_ClearFlag（PWR_FLAG_WU）;/* Wait until last write operation on RTC registers has finished */RTC_WaitForLastTask（）;/* Clear RTC Alarm interrupt pending bit */RTC_ClearITPendingBit（RTC_IT_ALR）;/* Wait until last write operation on RTC registers has finished */RTC_WaitForLastTask（）;/* Function Name ： dev_rtc_setAlarm* Description ： 设置RTC闹钟。* Input ： 闹钟时间* Output ： None* Return ： None*/void dev_rtc_setAlarm（u32 AlarmValue）/* Clear the RTC SEC flag */RTC_ClearFlag（RTC_FLAG_SEC）;/* Wait clear RTC flag sccess */while（RTC_GetFlagStatus（RTC_FLAG_SEC） = RESET）;/* Wait until last write operation on RTC registers has finished */RTC_WaitForLastTask（）;/* Sets the RTC alarm value */RTC_SetAlarm（RTC_GetCounter（） + AlarmValue）;/* Wait until last write operation on RTC registers has finished */RTC_WaitForLastTask（）;/* Function Name ： dev_rtc_isAlarm* Description ： RTC闹钟是否触发* Input ： None* Output ： None* Return ： TRUE：已触发，FALSE，未触发*/Boolean dev_rtc_isAlarm（void）if（g_bRTCAlarm）/* Clear the RTC alarm flag */g_bRTCAlarm = FALSE;return TRUE;return FALSE;void dev_iwdg_init（void）/* Enable write access to IWDG_PR and IWDG_RLR registers */IWDG_WriteAccessCmd（IWDG_WriteAccess_Enable）;/* IWDG counter clock： 40KHz（LSI） / 256 = 0.15625 KHz */IWDG_SetPrescaler（IWDG_Prescaler_256）;/* Set counter reload value to 1562 */IWDG_SetReload（1562）; / 10s/* Reload IWDG counter */IWDG_ReloadCounter（）;/* Enable IWDG （the LSI oscillator will be enabled by hardware） */IWDG_Enable（）;void dev_iwdg_feed（void）IWDG_ReloadCounter（）;/* Function Name ： dev_clk_restore* Description ： Restore system clock after wake-up from STOP： enable HSE， PLL* and select PLL as system clock source.* Input ： None* Output ： None* Return ： None*/void dev_clk_restore（void）/* Enable HSE */RCC_HSEConfig（RCC_HSE_ON）;/* Wait till HSE is ready */HSEStartUpStatus = RCC_WaitForHSEStartUp（）;if（HSEStartUpStatus = SUCCESS）/* Enable PLL */RCC_PLLCmd（ENABLE）;/* Wait till PLL is ready */while（RCC_GetFlagStatus（RCC_FLAG_PLLRDY） = RESET）/* Select PLL as system clock source */RCC_SYSCLKConfig（RCC_SYSCLKSource_PLLCLK）;/* Wait till PLL is used as system clock source */while（RCC_GetSYSCLKSource（） ！= 0x08）/* Function Name ： EXTI_Configuration* Description ： Configures EXTI Line3.* Input ： None* Output ： None* Return ： None*/void EXIT_Configuration（void）EXTI_InitTypeDef EXTI_InitStructure;GPIO_EXTILineConfig（GPIO_PortSourceGPIOB，GPIO_PinSource3）;EXTI_ClearITPendingBit（EXTI_Line3）;EXTI_InitStructure.EXTI_Line = EXTI_Line3;EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;EXTI_InitStructure.EXTI_LineCmd = ENABLE;EXTI_Init（EXTI_InitStructure）;void dev_exti_enable（Boolean bEnable）NVIC_InitTypeDef NVIC_InitStructure;/* Clear the Key Button EXTI line pending bit */EXTI_ClearITPendingBit（EXTI_Line3）;NVIC_ClearIRQChannelPendingBit（EXTI3_IRQChannel）;NVIC_InitStructure.NVIC_IRQChannel = EXTI3_IRQChannel;NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;NVIC_InitStructure.NVIC_IRQChannelCmd = bEnable ？ ENABLE ： DISABLE;NVIC_Init（NVIC_InitStructure）;/* Function Name ： main* Description ： Main program.* Input ： None* Output ： None* Return ： None*/int main（void）/* System Clocks Configuration */RCC_Configuration（）;/* NVIC configuration */NVIC_Configuration（）;/* Configure RTC clock source and prescaler */RTC_Configuration（）;/* Configure the SysTick to generate an interrupt each 1 millisecond */SysTick_Configuration（）;/* Configures EXTI Line3 */EXIT_Configuration（）;/* IWDG initialize*/dev_iwdg_init（）;while（1）/ 执行任务Task1（）;Task2（）;/ 。/ 喂狗dev_iwdg_feed（）;/ 进入待机模式开关if（m_bEnterStandByMode）/ 使能外部中断，GPIOB3，用以MCU从待机模式唤醒dev_exti_enable（TRUE）;ENTERSTOPMODE：/ 设置RTC闹钟，5秒钟产生一次RTC闹钟中断*/dev_rtc_setAlarm（5）;/ 进入停止模式（低功耗），直至外部中断触发时被唤醒PWR_EnterSTOPMode（PWR_Regulator_LowPower， PWR_STOPEntry_WFI）;/ 是否是RTC闹钟中断唤醒if（dev_rtc_isAlarm（）/ 喂狗dev_iwdg_feed（）;/ 喂完狗继续进入停止模式goto ENTERSTOPMODE;/ 禁止外部中断dev_exti_enable（FALSE）;/ 从停止模式唤醒后恢复系统时钟dev_clk_restore（）;